If you’re heading to see Britney Spears’ show in Las Vegas in the near future, there are one or two things you can more or less guarantee: bigger wigs than a ‘RuPaul’s Drag Race’ reunion special, a whole lot of strutting and a little assistance when it comes to the vocals.

But while fans may have accepted that Britney’s live shows are more about hair-flipping and oiled up dancers than actual live singing, a rep for the singer has been forced to deny that she’s been lip-syncing to Sia Furler’s vocals.